@Watershed. Noted your comments / observations. It does seem somewhat bizarre that a (walk up) "route via Liverpool" ticket from Newton-le-Willows to Chester would ever be valid for some itinerary which doesn't actually involve travelling via Liverpool. Thank you for the explanation as to why this would be possible.
Yes, I'll be the first to admit it's less than obvious - but it makes more sense when you break it down. There aren't any permitted routes that follow the specified routing so you have to work out how to travel to & from the via point.
This reminds me of the
case we saw in 2017 where a passenger held a Manchester to Andover ticket routed "via London" and was prosecuted for allegedly "being off route" due to using a XC service from Manchester to Basingstoke via Reading.
For a variety of reasons that prosecution was fundamentally flawed (and was ultimately withdrawn) but most notably, the "via London" fare
was in fact valid for avoiding London - as it was valid from Manchester to London via Birmingham and Reading, and from London to Andover via Reading and Basingstoke. As the ticket was a flexible walk-up, the passenger was under no compulsion to undertake the unnecessary double-back between Reading and London.
This is somewhat similar to the example following which ATOC infamously stated
"the routes "London" and "not London" are not necessarily mutually exclusive", in the early years of the Routeing Guide.
If the OP still wishes to travel outward via Warrington (BQ), might a one-way change of route excess from "route via Liverpool" to "route via Warrington" be the easiest way to achieve this? If so, reckon it would possibly cost an additional £2.50 (£1.65 with Railcard discount) for an Off Peak Day Return.
Yes, agreed - that would likely be the cheapest way. This excess could of course be obtained at any ticket office, or onboard the train without penalty